def FDBEul(currU, dW, FDMatSq, h, sigma):
B = sp.eye(len(currU)) - 1j * sum(dW) * FDMatSq
b = 1j * h
nextU = spla.spsolve(B, currU + b * sf.cubicU(currU, sigma))
return nextU
def FDFEul(currU, dW, FDMatSq, h, sigma):
A = sp.eye(len(currU)) + 1j * sum(dW) * FDMatSq
b = 1j * h
nextU = A.dot(currU) + b * sf.cubicU(currU, sigma)
return nextU
def PSFEul(currU, dW, kSq, h, sigma):
a = (1 - 1j * np.sum(dW) * kSq)
b = 1j * h
nextU = np.multiply(a, currU) + b * fft(sf.cubicU(ifft(currU), sigma))
return nextU
def PSExplExp(currU, dW, kSq, h, sigma):
nextU = np.multiply(np.exp(
-sum(dW) * 1j * kSq), currU) + 1j * h * np.multiply(
np.exp(-sum(dW) * 1j * kSq), fft(sf.cubicU(ifft(currU), sigma)))
return nextU
def PSBEul(currU, dW, kSq, h, sigma):
a = 1 / (1 + 1j * np.sum(dW) * kSq)
b = 1j * h / (1 + 1j * np.sum(dW) * kSq)
nextU = np.multiply(a, currU) + np.multiply(
b, fft(sf.cubicU(ifft(currU), sigma)))
return nextU
def FDExplExp(currU, dW, FDMatSq, h, sigma):
nextU = la.expm(1j * sum(dW) *
FDMatSq).dot(currU + 1j * h * sf.cubicU(currU, sigma))
return nextU